Stem Cells and Cellular Origins of Mammary Gland: Updates in Rationale, Controversies, and Cancer Relevance

Table 2

An overview of lineage-tracing studies defined MaSC markers and their cellular fate using different mouse models.

Study	Marked cells	Cellular fate of the MaSCs	Mouse model
Van Keymeulen et al. [15]	K14+	Embryonic: multipotent	K14-Cre/Rosa-YFP mice K14-rtTA/TetO-Cre/Rosa-YFP mice
	K14+	Postnatal: unipotent (myoepithelial/basal)	K14-rtTA/TetO-Cre/Rosa-YFP mice
	K5+	Postnatal: unipotent (myoepithelial/basal)	K5-CreER/Rosa-YFP mice
	Lgr5+	Postnatal: multipotent (most basal, rare luminal)	Lgr5-GFP-CreER/Rosa-Tomato mice
	K8+	Postnatal: unipotent (luminal)	K8-CreER/Rosa-YFP mice
	K18+	Postnatal: unipotent (luminal)	K18-CreER/Rosa-YFP mice
Van Amerongen et al. [18]	Axin2+	Embryonic: unipotent (luminal)	Axin2^CreERT2/+;R26R^mTmG/+ mice; Axin2^CreERT2/+;R26R^lacZ/+ mice
		Prepubety: unipotent (myoepithelial/basal)
		Puberty: multipotent
		Pregnancy: multipotent
Sale et al. [43]	Notch2+	Postnatal: multipotent (small and large cells) (unrecognized mammary epithelial cell populations)	N2-CreERT2^SAT/R26R^LacZ
Lafkas et al. [44]	Notch3+	Postnatal: unipotent (luminal)	N3-CreERT2^SAT/R26^mTmG mice
Rios et al. [36]	Elf5+	Postnatal: unipotent (luminal)	Elf5-rtTA-IRES-GFP mice; Elf5-rtTA/TetO-cre/R26R-Confetti mice; Elf5-rtTA/TetO-cre/R26R-tdTomato mice
	K5+	Postnatal: multipotent	K5-rtTA-IRES-GFP mice; K5-rtTA/TetO-cre/R26R-Confetti mice; K5-rtTA/TetO-cre/R26R-tdTomato mice
	K14+	Postnatal: multipotent	K14-creERT2/R26R-Confetti mice
	Lgr5+	Postnatal: multipotent	Lgr5-GFP-IRES-creERT2/R26R-tdTomato mice
Prater et al. [28]	Acta2+	Postnatal: unipotent (basal)	Acta2-Cre-ER^T2;Rosa26LacZ mice; Acta2–Cre–ER^T2; R26^mTmG mice
Rodilla et al. [41]	Notch1+	Embryonic: multipotent; Postnatal: unipotent (ER- luminal)	N1Cre^ERT2R26^mTmG mice
Chang et al. [45]	Wap+	Pregnancy: unipotent (ER- luminal)	WAP-Cre;Rosa26-lsl-YFP mice
Wang et al. [29]	Procr+	Postnatal: multipotent	Procr^CreERT2/+;R26^mTmG/+ mice; Procr^CreERT2/+;R26^DTA/+ mice
Wuidart et al. [39]	K14+	Postnatal: multipotent	K14-CreER^T2/Rosa-Confetti mice
	K19+	Postnatal: multipotent (most luminal, rare basal)	K19-CreER^T/Rosa-Confetti mice
	Sox9+	Postnatal: multipotent (most luminal, rare basal)	Sox9-CreER^T2/Rosa-Confetti mice
	Lgr5+	Postnatal: multipotent	Lgr5-CreER^T2/Rosa-tdTomato mice
	Lgr6+	Postnatal: multipotent	Lgr6-CreER^T2/Rosa-tdTomato mice
Wang et al. [46]	Sox9+	Postnatal: multipotent (myoepithelial/basal, ER- luminal)	Sox9-CreER^T2;R26R-tdTomato mice
	Prom1+	Postnatal: unipotent (ER+ luminal)	Prom1-CreER^T2;R26R-tdTomato mice
Sreekumar et al. [47]	p63+	Postnatal-Cap cells: unipotent (basal)	p63^CreERT2/+;Rosa^mTmG/+
Van Keymeulen et al. [49]	ER+	Postnatal: unipotent (ER+ luminal)	ER-rtTA/TetOH2B-GFP mice; ER-rtTA/TetOCRE/Rosa-YFP mice
Elias et al. [50]	Blimp1+	Embryonic: unipotent (luminal); Postnatal: unipotent (ER- luminal)	Prdm1Cre^ERT2/+; R26R^mTmG/+
Wuidart et al. [48]	p63+	Embryonic: unipotent (basal)	K14rtTA/TetO-Cre/Rosa-Δ Np63-IRES-GFP
Lilja et al. [42]	Notch1+	Embryonic: unipotent (luminal); Postnatal: unipotent (ER- luminal)	N1Cre^ERT2/R26^mTmG mice

K14: keratin14; K5: keratin5; K8: keratin8; K18: keratin18; K19: keratin19; Elf5⁺: E74-like factor 5; Acta2: actin, alpha 2, smooth muscle, aorta; WAP: acidic protein; Procr: protein C receptor; Sox9: SRY-box 9; Lgr6: leucine-rich repeat-containing G protein-coupled receptor 6; Prom1: prominin 1; p63: tumor protein p63; ER: estrogen receptor1; Blimp1: PR/SET domain 1.